Raptors are easily one of the most popular types of dinosaur. With their terrifying sickle killer claws and ultra-fast running speeds, it’s easy to see why. However, there exists a far more terrifying group known as the megaraptors (“giant thieves”). As the name implies, they are essentially huge versions of the regular types, with murderous claws more than 30 centimeters (12 inches) in length.

Little is known about their evolutionary history, however, so it’s always good news when another fossil has been found. As detailed in PLOS ONE, a new megaraptor has just recently been discovered, and it’s just as scary as its contemporaries.

A partial skeleton with a wonderfully preserved skull was unearthed in Patagonia by a group of paleontologists from the University of Alberta (UoA), Canada and the National Scientific and Technical Research Council (CONICET) in Argentina. Dated to be 80 million years old, this carnivorous beast living during the Late Cretaceous period, the twilight chapter in the age of the dinosaurs.

Like its cousins, this new dinosaur – Murusraptor barrosaensis – has air-filled, birdlike bones, indicating it was an agile hunter. Incredibly, despite the fact that it is 8 meters (26 feet) long, the researchers think that its bone structure indicates that it is a juvenile, not a fully-grown adult. The authors write that “in spite being immature, it is a larger but more gracile animal than existing specimens of Megaraptor.”

In addition, with its 9-centimeter-long (3.5-inch-long) razor-sharp teeth, it’s unlikely any prey would survive after being bitten with its frightening jaw.

As cool as discovering a new non-avian dinosaur is by itself, the key question for the researchers was how it fitted into its section of the evolutionary tree. There is currently a huge debate as to what group of dinosaurs these megaraptors belong to, and there are no clear answers at present. They either belonged to the “superfamily” Allosauroidea on one hand or the Coelurosauria group on the other, the latter of which contains the most famous dinosaur of all, the Tyrannosaurus rex.

A silhouette of the new megaraptor. The white-shaded bones indicate those preserved within the fossil. Coria et al./PLOS ONE

Unfortunately, this new fossil still doesn’t settle the debate. After comparing its skeletal features to a wide range of other potentially related dinosaurs, there just aren’t enough common physical features – technically known as synapomorphies – to make a conclusive decision as to which group M. barrosaensis resides within.

Philip Currie, one of the co-authors of the paper and a renowned paleontologist from UoA, has previously said that it’s highly likely that all Coelurosauria were feathered. If the new specimen was indeed part of the Coelurosauria group, it is likely that it was adorned with at least a small degree of plumage.

Going by what its cousin Orkoraptor probably looked like, this new monstrous being would resemble a rather demonic, furry Dr. Seuss character.